Sorry for your loss. If your wife lived during 2021, you can still file "married filing jointly" and the deduction that goes with it. Check that box on the 1st page of the 1040. Then you will have to enter her electronic signature to approve the return. IRS is OK with that. If she died in 2020, you cannot elect that option. And for 2022, you'll be filing single unless you marry.
Sorry again for your loss.
